DESCRIPTION: (Applicant's Description) The purpose of the Animal Core is to provide in a cost effective, centralized and standardized manner, a series of murine xenograft models that will be used by investigators in the program project. The animal core will be a centralized resource to support the in vivo and preclinical studies proposed in Projects 1 to 4. The core will provide the following services: (1) purchasing and boarding of all animals required by the projects; (2) standard injections of tumor cells in mice using established tumorigenic and metastatic models; (3) administration of therapeutic agents/biological modifiers to be tested in preclinical studies and monitoring of tumor growth; and (4) euthanasia and preparation of material for the Pathology Core. In addition, the core will provide a reliable quality control mechanism to ensure that mice have the proper background and remain pathogen free.